HDF Scattered Light Subtraction: version 1

In version 1 of the data reduction, our approach to dealing with scattered
light is the following:

For F814W we reject all frames with visible scattered light. This
consists of 19 frames totaling 25% of the observing time. Most of that
will be recoverable with careful subtraction of the X pattern.

For F606W we reject all the frames with visible scattered light. This
consists 18 out of 123 frames, and constitutes 6.5% of the exposure time.
The X pattern in most of the F606W frames is very prominent (most of
these short exposures were planned as scattered light calibrations),
and it is probably not worthwhile to try to use these frames in the
final stack.

For F450W we reject all frames with visible scattered light. This
consists of 26 frames totaling 24% of the observing time. Most of that
will be recoverable with careful subtraction of the X pattern.

For F300W use all the data, but
produce two versions of the drizzled image, one
with the scattered light pattern, and the other with the scattered
light pattern removed. Scattered light removal was done by masking
from the F300W images all sources present in the F450W frames, then
smoothing the background with a running Gaussian. We expect this
to serve only for cosmetics, and will come back and do a more careful
job in the coming weeks.